Pressed powders, eye shadow, blushes and face powders currently on the market are produced by compressing loose powder into a metal pan using direct pressure. The pan containing the pressed powder cake is then glued into the compact, which is the primary container.
In the conventional process the pressure used in the pressing operation must be maintained within precise limits. If the pressure is too great, the metal pan may be distorted and must be discarded. In addition, utilizing a high pressure results in a cake which lacks the desired "pay off" characteristics. On the other hand, if the pressure is too low, the pressed cake will lack cohesive strength. Thus, certain powder compositions cannot successfully be used as a pressed powder cake because the pressure required to obtain the necessary cohesive strength will either distort the metal pan or produce a cake that is so hard that it lacks "pay-off".
As a further problem, aerobic bacteria may frequently contaminate the pressed pans, so that the pans must be sterilized before final assembly either by heat or other techniques. This further adds to the cost in producing the pressed powder product.